1971 PONTIAC TEMPEST

Typical onset: 70,000-110,000 mi

Symptoms: Delayed engagement when shifting into drive or reverse, Slipping between gears under acceleration, Burnt transmission fluid smell and dark brown or black fluid color, Complete loss of forward gears, often starts with second gear only

Fix: The factory transmission oil cooler inside the radiator frequently corrodes and fails, starving the transmission of proper cooling. If caught early, replacing the cooler and flushing costs 3-4 hours labor. Most cases we see need full rebuilds because owners ignored early symptoms. TH350/TH400 rebuild runs 12-16 hours with clutch packs, bands, seals, and torque converter. External cooler installation is mandatory on rebuild to prevent repeat failure.

Estimated cost: $2,200-3,800

Typical onset: 90,000-150,000 mi

Symptoms: Blue smoke on startup that clears after warmup, Burning a quart of oil every 500-800 miles, Fouled spark plugs, especially cylinders 3, 5, and 7, Loss of compression showing 20+ PSI variance between cylinders

Fix: Original ring technology and valve seals don't hold up like modern engines. Rings lose tension and oil control. A proper ring job requires pulling the engine, decking heads, honing cylinders, and replacing all rings and bearings. Figure 20-24 hours labor for complete disassembly, machine work, and reinstallation. Valve seals alone are a band-aid that buys 10,000 miles maximum. The 400 and 455 V8s are particularly prone due to larger bore sizes.

Estimated cost: $3,500-5,200

Typical onset: 80,000-140,000 mi

Symptoms: Deep knocking sound from bottom end, worst at idle when warm, Metallic rattling that increases with RPM, Sudden oil pressure drop below 10 PSI at idle, Metal shavings visible in oil filter media

Fix: Pontiac V8s use a rope-style rear main seal that leaks oil and lets dirt contaminate the system. When oil changes are stretched or low oil levels run too long, the center main bearings go first. Requires full engine removal for crank R&R, turning or replacement, bearing installation, and careful clearance checking. 24-30 hours total. Often discover cam bearings are also damaged during teardown, adding cost. The 250 I6 has similar issues but less catastrophic.

Estimated cost: $4,000-6,500

Symptoms: Hard starting when engine is hot, starts fine cold, Stumbling or hesitation on acceleration from stop, High idle that won't come down even when warm, Black smoke and raw fuel smell indicating rich running

Fix: Ethanol fuel destroys original rubber components, cork floats, and accelerator pump diaphragms. The Quadrajet's needle-and-seat wears and floods the engine. Complete carburetor rebuild with modern ethanol-compatible kit takes 2-3 hours if you catch it before it damages the intake gaskets. Most shops see these every 30,000-40,000 miles now due to fuel quality. Much more frequent than original service intervals.

Estimated cost: $350-650

Symptoms: Clunking noise when shifting from park to drive or reverse, Visible body separation from frame, especially at rear, Transmission shifter vibration transmitted through console, Doors misaligning or difficult to close after 50+ years

Fix: Rubber mounts disintegrate with age regardless of mileage. Transmission mount replacement is straightforward at 1.5-2 hours, but body mounts require jacking the body, cutting rusted bolts, and dealing with rotted mount pockets. Budget 8-12 hours for all body mounts if doing them correctly with frame cleaning and rust treatment. Transmission mount should be replaced during any transmission service.

Estimated cost: $800-1,800

Symptoms: Intermittent stalling after 15-20 minutes of driving, Engine dies under load then restarts after sitting, Weak fuel pump pressure below 5 PSI, Rough idle that improves briefly after adding fresh fuel

Fix: Cars sitting for extended periods develop varnish throughout the fuel system. In-tank sock filter clogs, mechanical fuel pump check valves stick, and fuel lines build internal restrictions. Proper fix requires dropping the tank, cleaning or replacing it, new fuel pump, all rubber lines, and multiple filter changes in the first 500 miles. Tank removal and reinstallation is 4-5 hours, plus pump and line work adds another 2-3 hours.

Estimated cost: $600-1,200